The global use of petroleum hydrocarbons for energy and raw materials in various applications has increased with extensive release of a wide variety of contaminants into the environment, affecting soil, surface water and groundwater. The effect results to numerous health, ecological and environmental issues. However, treatment of contamination and pollution caused by petroleum hydrocarbons is a huge and laborious work. It involves several in situ or ex situ treatments comprising containment, separation and destruction which include biological, chemical, physico-chemical, thermal and heat, electric and electromagnetic, acoustic and ultrasonic treatment methods. These treatment methods involve several other techniques and strategies as listed in this review. The health risks pose by petroleum hydrocarbon pollution have driven scientists to research, develop and implement risk-based remediation strategies for restoration and reclamation of affected environments. To select the best treatment option for remediation, it is important to comprehend the nature, composition, properties, sources of pollution, type of environment, fate, transport and distribution of the pollutants, mechanism of degradation, interaction and relationships with microorganisms, the intrinsic and extrinsic factors affecting remediation. It helps to evaluate and predict the chemical behaviour of the pollutants with the short and long-term effects and mitigate the effects of pollution and limit exposure to the pollutants. Despite the available remediation options for petroleum hydrocarbon management and removal, sufficient and complete remediation can be implemented by adoption of proper approach derived from risk-based management procedure that can be practical, scientifically defensible, widely adapted, sustainable, non-invasive, eco-friendly and cost-efficient. This paper provides an overview of the various remediation and treatment technologies derived from risk-based approaches that are used for isolation, containment, separation, restoration reclamation and remediation of soil, sediments, surface water and groundwater contaminated by petroleum hydrocarbons and organic compounds.

Remediation of soil and water contaminated with petroleum hydrocarbon: A review

Remediation of soils and sediments polluted with polycyclic aromatic hydrocarbons: To immobilize, mobilize, or degrade?

The environment pollution with hydrophobic hydrocarbons is a serious problem that requires development of efficient strategies that would lead to bioremediation of contaminated areas. One of the common methods used for enhancement of biodegradation of pollutants is the addition of biosurfactants. Several mechanisms have been postulated as responsible for hydrocarbons bioavailability enhancement with biosurfactants. They include solubilization and desorption of pollutants as well as modification of bacteria cell surface properties. The presented review contains a wide discussion of these mechanisms in the context of alteration of bioremediation efficiency with biosurfactants. It brings new light to such a complex and important issue.

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The Impact of Biosurfactants on Microbial Cell Properties Leading to Hydrocarbon Bioavailability Increase

Currently, there are different remediation technologies for contaminated soils, but the selection of the best technology must be not only the treatment efficiency but also the energy consumption (costs) during its application. This paper is focused on assessing energy consumption related to the electrochemical treatment of polluted soil with petroleum hydrocarbons. In the framework of a research project, two types of experiments were conducted using soil that was artificially contaminated with diesel fuel at the same level of contamination. The experimental conditions considered for each experiment were: different amounts of contaminated soils (6 kg and 18 kg, respectively), the same current intensity level (0.25A and 0.5A), three different contamination degrees (1%, 2.5% and 5%) and the same time for application of the electrochemical treatment. The remediation degree concerning the removal of petroleum hydrocarbons from soil increased over time by approximately 20% over 7 days. With regard to energy consumption, the results revealed that with an increase in the quantity of treated soil of approximately three times, the specific energy consumption decreased from 2.94 kWh/kg treated soil to 1.64 kWh/kg treated soil.

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Decontamination of Petroleum-Contaminated Soils Using The Electrochemical Technique: Remediation Degree and Energy Consumption.

From the perspective of characteristics and causes, probability and forecast, and safety management evaluation, this paper analyzes 3974 hazardous chemical casualty accidents that occurred between 2006 and 2017 in China. The trends, monthly and hourly distributions, lifecycles, chemical and accident types, and the direct and indirect causes of casualty accidents are analyzed first. To estimate the probability of casualty accidents, the Poisson regression model is employed. The time series model is developed to forecast the number of casualty accidents. The safety management of hazardous chemicals is evaluated based on an inverted U-shaped curve that fits the relationship between the number of casualty accidents and petrochemical industry outputs. Moreover, measures for improving the safety management of hazardous chemicals are provided based on the analysis, forecast, and evaluation. The results show that the probability of 200–600 casualty accidents occurring per year in China is 59.10%. Sixteen of thirty provinces are identified as having better safety management with regard to hazardous chemicals.

An Analysis of Hazardous Chemical Accidents in China between 2006 and 2017

Soils contaminated with toxic and persistent pollutants pose different and serious hazards to the environment and human health. Multidisciplinary procedures that are considering models for the prediction of risk for long-term exposure are needed. The present paper illustrates the operating mode and utility of an environmental software able toe0) integrates the dose-response modeling as a major part of hazard characterization in order to assess the quantitative risk from carcinogens. In this way, risk assessment is used as a method for the investigation of contaminated sites. The method is demonstrated on a Romanian field site, contaminated with petroleum products. For the assessment of human health risks from oil-contaminated sites, the contaminants of concern are considered as polycyclic aromatic hydrocarbons (PAHs), monocyclic aromatic hydrocarbons (MAHs), and heavy metals, chemicals known as human carcinogens. Quantitative risk calculations revealed an individual risk of 1.07 × 10−5 for children and 6.89 × 10−6 for adults. The paper represents a utility example of an environmental software solution that could be considered by decision-making factors in approving certain projects. The software tool is helpful for protecting the environment and human health.

Crude Oil Contaminated Sites: Evaluation by Using Risk Assessment Approach

The present work addresses the assessment of human health risk from soil contaminated with total petroleum hydrocarbons (TPHs) due to crude oil pollution, with a particular focus on the polycyclic aromatic hydrocarbon (PAH) group of carcinogenic and toxic substances Given that the measured risk for human health exceeded the accepted level, the study considered an electrochemical remediation method The laboratory-scale experiments were conducted by using an electric field-based treatment as a possible solution for the remediation of contaminated soil After 20 days of treatment, while the voltage applied was 15 V (specific voltage of 1 V/cm), the hydrocarbon content was significantly reduced The parameters measured to determine the overall remediation efficiency were pH, redox potential, ionic strength, soil characteristics, voltage gradient, and zeta potential The remediation degree observed during the experiments was around 50% for TPHs and 46% for PAHs The applied remediation method resulted in significant removal efficiency of the tested contaminants from the soil Consequently, the human health risk assessment for the new degree of contaminants in the soil was achieved This data demonstrated to what extent the application of the remediation applied technology ensured an acceptable risk under the same exposure conditions for the industrial workers

Mihaela Alexandra Stoian

Papers

Crude Oil Contaminated Sites: Evaluation by Using Risk Assessment Approach

Minimizing the Health Risks from Hydrocarbon Contaminated Soils by Using Electric Field-Based Treatment for Soil Remediation